Who Will Show Up?
A third of U.S. Coast Guard helicopters can reach about 300 miles off the coast — farther if they can refuel mid-ocean — while the remainder of the fleet can respond up to 170 miles offshore. If the helicopter responding was already airborne on a law-enforcement mission, they may not have a rescue swimmer aboard. Coast Guard cutters are also stationed far offshore. Coast Guard airplanes can reach 1,000 miles from any major airstrip, worldwide. They're likely to be first on scene far offshore. They can drop handheld radios, safety equipment, water and provisions, dewatering pumps and life rafts.
Air National Guard helicopters refuel in midair in settled weather, greatly extending their range, and U.S. Navy assets are available to the rescue coordination center as well. Foreign rescue craft respond in foreign waters. Beyond 300 miles from the U.S. coast, rescue may be from a merchant ship. The Amver system monitors more than 21,000 ships from 140 nations — 40 percent of the world's merchant fleet. On average, 3,900 participating ships are at sea at any given moment, eager to respond to any high-seas emergency. An Amver ship may respond even when close to shore if the RCC deems it the best and closest resource.
Spot Versus PLB
Spot — It's smaller than a PLB and adds limited one-way communication and GPS tracking with user-replaceable AA lithium batteries. Coverage is limited to most major landmasses and adjacent offshore waters (though not mid-ocean), except for India and eastern Africa. Spot boasts very good (but not 100 percent) likelihood of each message being sent. GPS positions are more accurate than those from a PLB but are updated only every five minutes, and Coast Guard aircraft can't use that signal, even for homing. Spot may take 15 minutes for the first GPS fix.
» Price: $100 for a basic device plus $100 per year. Add $50 per year for tracking plus other subscription services.
PLB — It's built to robust government specifications and is USCG monitored. It comes as close to a guarantee of rescue as any device allows. The first GPS fix comes less than a minute from first activation and is updated every 50 seconds. ACR offers a subscription-based "I'm OK" e-mail or text message, triggered by each PLB test (406link.com), but it's limited to about one per month for battery conservation. A PLB GPS test also includes coordinates but wastes far more battery power.
» Price: About $300 (with GPS) and $100 every five or six years for a new battery as well as a test of electronics and watertight seal.